Switch stick mounted load break



June 9, 1959 s. R. SMITH, JR., ET AL 2,890,313

SWITCH STICK MOUNTED LOAD BREAK Filed Oct. 11, 1957 I5 Sheets-Sheet 1June 9, 1959 s. R. SMITH, JR., EIAL 2,890,313

SWITCH s'rxcx MOUNTED LOADBREAK Filed Oct. 11, 1957 3 Sheets-Sheet 2June 9, 1959 s. R. SMITH, JR., ETAL ,8 ,3

SWITCH STICK MOUNTED LOAD BREAK Filed Oct. 11, 1957 3 Sheets-Sheet 3 5'I nfim ors,

idne Rsmifhafm Franc? d. C'fzqr'ewicz, 5 7M P. w

United States Patent SWIT'CH STI'CK- MOUNTED LOAD BREAK Sidney R. Smith,Jr., Stockbridge, and. Francis J. 'Charewicz, Lanesboro, Mass, assignorsto General Electric Company, a corporation of New York ApplicationOctober 11, 1957, Serial No. 689,724

13 Claims. (Cl. 200-148) This invention relates to aswitch stick mountedload break, and more particularly, to a switch stick mounted load breakdevice for circuit interrupters such as opentype' disconnect switchesand open-type cutouts.

The instant patent application is a continuation-in-part of ourcopending patent application, Serial No. 609,219, which was filed onSeptember 11, 1956, now Patent No. 2,834,856, and which is assigned tothe same assignee as the instant patent application.

Switch stick mounted load break devices are not new per se. However,prior art switch stick mounted load break devices have severaldisadvantages, and it is an object of this invention to provide animproved switch stick mounted load break device which will overcomethese disadvantages.

One disadvantage of prior art switch stick mounted load break devices isthat they tend to be complicated in that they utilize a large number ofparts. This means that the devices are not lightweight and low cost.Additionally, the devices are more apt to stick or jam due to the largenumber of moving parts.

Another disadvantage of prior art switch stick mounted load breakdevices is that they require some modification in conventional switchesor cutouts before they can be used.

A further disadvantage of prior art switch stick mounted load breakdevices is that the switchor cutout with which the load break device isbeing used cannot be reclosed in the event the load break devicemalfunctions. For instance, in one prior art form of switchstick mountedload break device it is possible for the contacts of the load breakdevice to become welded together or for the operating device to becomejammed after the load break device has been expanded in order to openthe switch or contact and at this stage the switch or cutout cannot bereclosed.

In our invention we overcome the above discussed disadvantages byproviding a switch stick mounted load break device which has a minimumnumber of parts whereby the device is both lightweight and low cost.Additionally, the device has a minimum number of moving parts wherebythere is very little chance for the load break device to stick or jam.The loadbreak device can be used with a large variety of existingopen-type switches or cutouts without requiring any modification intheswitches or cutouts. Additionally, due to the uncomplicated nature ofthe load break device and the arrangement of the various parts, thecutout or switch can be readily reclosed in the event the load Ibreakdevice fails to interrupt the electrical arc.

Broadly, our invention comprises an expendable and replaceableelectrical arc extinguishing member which is mounted on the endof aswitch stick. The expendable and replaceable electrical arcextinguishing member may comprise a fluid pressure blast generatingcartridge or a fuse cartridge such as disclosed in copending' Smith andCarpenter patent application- Serial Number 78,9 95 filed-- FatentedJune 9, 1959 April 18; 1956, now Patent 2,834,855, and assigned tothesame assignee as-t-he instant patent application, and our heretoforementioned copending patent application. The fluid pressureblastgenerating cartridges may utilize compressed gas, gun powderor achemical substance which will generate gasesand' liquids under-pressure.The fuse cartridges may be used to interrupt the circuit merely bymelting ofthe fusible-element.

The features of our invention which we believe to be novel are set forthwith particularity in the appended claims. Our invention itself,however, both asto its organization and method of operation, together.with further objects and advantages thereof, may best be understood byreference to the following description taken in connection with theaccompanying drawings.

In the drawings, Fig. 1 is. an elevation. view of. one form of ourinvention. Fig. 2 is atop View when looking in thedirection of arrow 2of Fig. 1'. Fig. 3 is atop view of the switch stick mounted load breakdevice of Fig. 1". Fig. 4 is a side view of the switch. stick mountedload'break device when looking in the direction of arrow 4"- of Fig. 3.Fig. 5 is another side view of. the switch stick mounted load breakdevice when looking. in. the direction of arrow 5 of Fig. 4. Fig. 6 isatop view of another form ofswitch stick mounted load break device. Fig.7 is aside view when looking in the direction of arrow 7 of Fig. 6".Fig. 8- is a top view of another form of switch stick mounted load breakdevice. Fig. 9 is aside view when. looking in the direction of arrow 9'of Fig. 8. Fig. 10 is a side view of another form of oun'inve'nti'onaFig. 1:1. is another side view of the switch stick mounted. load breakdevice of Fig. 10 when looking; in the. direction of arrow 11 of Fig.10. Fig. 12 is anelevation view of another form of switch stick mountedloadbreak device.

Referring. now particularly to Fig. 1, illustratedtherein is acon'ventionalformof.open-type fused cutout. This form of circuitinterrupter is particularly described inconstructionand operationinStrobel Patent 2,685,013 issued July 27, 1954 and assigned to the sameassignee as the instant invention.

Generally speaking, the circuit interrupter comprises an elongatedelectrical insulator 1 having a fuseholder 2. mounted thereon. The upperend of the insulator has a latch. element 3 whichalso serves the purposeof a contact, and the lower end of the insulator has a hinge element 4which also serves the purpose of a contact. The fuseholder 2 spans thelatch 3 and hinge 4 to complete an electrical circuit therebetween. Thecircuit interrupter' is. adapted to be suspended. from the crossarm of anot shown line pole by virtue of a mounting strap 61 which is connectedto the central portion. of the insulator by a clamping band 5. Thecontact latch 3- is provided with a line terminal 7 and combinationhinge and contact 4. is provided with a line terminal 8. The circuitinterrupter is adapted to protect an electrical apparatus such as a notshown line pole mounted transformer by connecting the terminal 7 to thedistribution line and the transformer to the terminal 8. If anovercurrent should develop in the protected transformer a fuse link 9 infuseholder 2 will melt which will permit the fuseholder to unlatchitself from the latch 3 and drop open, said overcurrent beinginterrupted in the fuseholder 2 by expulsion. action.

The fuse assembly makes electrical contact at its upper end with contactlatch 3 by virtue of a contact cap 11. At its lower end the fuseassembly is provided with a generally L-shaped member 12 which is hingedat its upper end to the fuseholder at the pivot point 13, and its lowerleft-hand end to the hinge element 4 by virtue of a pair of trunnions 14which fit in a pair .of bearing grooves 15 formed in the hinge element4. The fuse link 9 is brought out of the lower open end of the fuseholder of the fuse assembly and is tautly fastened to the member 12. Thefuseholder and member 12 comprise a toggle which is released when thefuse link 9 melts whereby the fuse assembly can move downwardly tounlatch itself and then drop open.

The fuseholder, which is a switch member as well as an overcurrentinterrupting means, is provided at its upper end with an eyelet handle16 which is electrically connected to the contact cap 11 by means suchas a spring 10. In other conventional forms of this type of circuitinterrupter the handle 16 may be integrally formed with the contact cap11. These parts are usually electrically interconnected so as toprohibit carbon tracking along the fuseholder between the elements 11and 16 and also to prohibit the formation of corona at the handle 16 andresultant radio interference noise.

The switch stick 20 minus the load break device which is mounted thereonis conventional. That is, it comprises a long electrically insulatedpole which can be made from wood or the like. On its upper end it has acap 18 which is provided with a hook 21 which is adapted to engage theeye of the handle 16. Within certain limits of load current and powerfactor the load can be manually broken by swinging the fuse assemblyopen with the switch stick. When this is done, an electrical arc may beestablished between the contact latch 3 and the contact cap 11. When theload current is high enough and the power factor low enough thiselectrical arc may not go out even though the fuse assembly is swung tothe full open position. This electrical arc has a deleterious effect onthe various parts of the circuit interrupter and is a threat to thesafety of the lineman and may result in an outage. For instance, asudden gust of wind may blow the arc into the lineman or into a groundedelement. The load break device provides a positive means for rapidextinction of the load current are even though the load power factor islow and the current magnitude is as high as the continuous currentrating of the cutout, thus minimizing these hazards.

The load break device comprises an expendable and replaceable electricalarc extinguishing or interrupting cartridge member 22 which is held by acartridge holder 23 which in turn is carried by an arm 17 which isresiliently mounted on the cap 18 of the switch stick 20. For instance,the cartridge 22 may comprise a small capsule of compressed electricalarc extinguishing gas such as carbon dioxide. The cartridge 22 may beprovided with a thin walled tip 24 which will be burned through when anelectrical arc terminates thereon. A pivot pin 25 may be provided on thecap 18 for resiliently and pivotly mounting the arm 17. The arm 17 isresiliently biased to the Fig. 4 position by a spring 19 which surroundsthe pin 25 and at its opposite ends bears against the arm 17 and the cap18.

The arm 17 is not biased by the spring 19 beyond the Fig. 4 position byvirtue of a stop 26 formed on the arm 17. The switch stick mounted loadbreak device is used by first holding it in an upright position andengaging the hook 21 with the eyelet handle 16. Then the operator canback off slightly from the circuit interrupter which will place theswitch stick 20 in a more or less diagonal position and rotate the arm17 in a clockwise direction whereby the spring 19 is tensioned. Ofcourse, the spring 19 tends to continuously urge the arm 17 back to itsidle position indicated in Fig. 4. This means that during the manualload break operation the parts 17, 23, 22 and 24 are successivelyengaged with the contact latch 17. Accordingly, the tip 24 will be thelast point of electrical contact between the fuse assembly and thecontact latch 3 whereby the electrical arc will terminate on the tip 24.When an electrical arc plays on the tip 24 it is punctured whereby thecompressed gas therein is released to cool and deionize the electricalarc.

The gas blast for extinguishing the electrical arc does not necessarilyhave to be initiated electrically by having the electrical arc terminateon the tip 24. For instance, the gas blast could be initiatedmechanically. This could be accomplished by making the tip 24 frangibleenough so that when it rides along the forward edge of the contact latch3 it is mechanically broken to release the compressed gas from withinthe cartridge into the electrical arc.

As indicated in Fig. 4 in its idle position the arm 17 extends in adirection which is generally parallel to the lengthwise axis of thestick 20, and then it is curved in a direction which is generallytransverse to the axis of the stick. This is so that the parts 17, 23and 22 will be disposed above the contact latch 3 as indicated in Figs.1 and 2 and ride along the forward edge of the contact 3. It is alsopossible to have these parts ride along the undersurface of the contactlatch 3 or along a side edge of the latch 3. A side edge acting loadbreak device is illustrated in Figs. 8 and 9. A switch stick mountedload break device whose elements ride along the underside of the latch 3is not preferred since one which rides along the front or side edges ofthe latch 3 is less apt to interfere with quick reclosure of the switchin the event the load break device malfunctions. Malfunctioning of theload break device could be caused by a defective cartridge. There isvery little chance of mal functioning of the device due to the otherload break parts inasmuch as only a single movable part 17 is utilizedwhich means that the load break device will not be apt to malfunctiondue to sticking or jamming of the parts. However, if the load breakdevice does malfunction it will not interfere with quick reclosure ofthe switch member. Reclosure of the switch member can be accomplished byquickly moving the switch stick to a vertical position so that theelements 17, 23 and 22 do not catch under the latch 3 and then pushingupwardly to slam the switch member 2 closed.

The circuit interrupter is an automatically operable fused protectorwhich is utilized in distribution systems to provide protection forelectrical apparatus which is on a branch or section of a maindistribution line. However, the invention is not restricted in itsapplicability to automatically operable switches or fused switches. Forinstance, the switch member 2 could comprise a plain disconnect switchblade or knife. All known commercial forms of such switches utilize aneyelet handle similar to the element 16 and a contact latch similar tothe element 3. Therefore, the load break device of the instant inventionis believed to have substantially universal application withoutrequiring any modification in distribution system switches which arepresently available on the market.

Without the load break device when the switch member 2 is opened with aconventional switch stick an arc would be drawn between the latch 3 andthe switch memher 2. These types of distribution system switchesordinarily are not designed or intended to be used as manual load breakdevices. Therefore, the electrical arc may not go out even though switchmember 2 is moved to the fully opened position. Accordingly, in order todisconnect the electrical apparatus from the energized line it may benecessary for the lineman or operator to open a main breaker back in themain line. Of course, this results in a service interruption on allbranches of the main line. Our invention overcomes this disadvantage byproviding an effective manual load break device for the branch protectoror switch whereby a main breaker need not be relied upon to interrupt abranch or section of the main line.

The switch stick mounted load break device can be used on a conventionalswitch stick which is indicated by the elements 18, 20 and 21. This canbe accomplished by providing an upstanding ear. 27 and an up standingplate 28 on the cap" 18. The elements 27 and 28 are for the purpose ofreceiving; the pivot pin 25 for the arm- 17. The plate 28 is given alarge enough dimension so that it will serve as a barrier orwallbetween' the arm 17 of the load break device: and the handle 16 ofthe switch member so that the element 16 does notinterfere with properfunctioning of the arm 17.

It will be appreciated that the switch stick 20 is still adapted toperform its conventional function even though the load break device ismounted thereon. The load break device which is mounted on the cap 18may comprise a special fitting which can be fitted on the opposite endof a' conventional switch stick if so" desired.

The construction and mode of. operation of the second form of theinvention illustrated in Figs. 6 and 7 is similar to that of the firstform of the invention except that a single spring element 30. issubstituted for the parts 17, 19 and 26 of the first form of. theinvention. The spring 30 has an internal arm extension 30' which vserves the function of the arm 17, and an integral curved portion .30"which serves the function of the stop 26 of the arm 17.

The third form of the. invention which is illustrated in Figs. 8 and 9provides a further simplification of the first and second forms of theinvention and an additional advantage in that it better lends itself foruse from either the right or left-hand side of theswitch member. Theload break device consists of merely an arc interrupting orextinguishing cartridge 22 which is held by the holder 23 which in turnis mounted on a conventional switch stick 18, 20 and 21 by a spring" armelement 31. The spring element 31 has a curved end which extends in adirection which is generally transverse to the lengthwise axis of thestick 20. However, this curve portion of the arm 31 also extends in adirection which is generally parallel to the hook 21 as contrasted totransverse thereto as in the first and second forms of the invention;This makes it possible to use the combinedswitch stick and load breakdevice at quite a distance from either side of the switch member as wellas from in front of the cutout. Of course, the elements 31', 23 and 22will ride successively along a side edge of the contact latch 3. Whenreclosing the circuit interrupter in order to avoid catching of theparts 22', 23 and 31,011 the underside of the latch 3 it will benecessary to tilt the switch stick slightly sideways. If the switchstick is tilted sideways when the switch is being opened then the arm.31 doesnt have to be resilient but can be made rigid.

The fourth form of the invention illustrated in Figs. and 11 is acombination of the advantages of the second and third forms of theinvention in that it provides a single spring element 32 similar to thespring 30 with integral stops 32', but its opposite ends are bent toprovide a pair of arms 32" and 32" which carry a pair of cartridges 22.These arms 32" and 32" are bent into a closed loop to provide sideguides around the contact latch 3. The arms 32" and 32 are fastenedtogether by a clip 33 to close the loop and from this point the arms 32"and 32 are extended in opposite directions which extend transverse tothe lengthwise axes of the stick 20 and hook 21. Accordingly, the outerends of I the arms and the cartridge holders 23 and cartridges 22 willride successively along the front edge of the contact latch 3. The sidesof the arms which extend in a direction which is generally parallel withthe lengthwise axis of the stick 2% provides side guides along the sideedges of the contact latch 3 for the load break device. At its upper endthe loop which is defined by the arms 32 and 32" is widened toaccommodate the contact latch 3. The double cartridges are an advantagein that if one of the cartridges should prove to be defective and failto interrupt the electrical arc the circuit interrupter can beimmediately closed and the switch stick 20 reversed to interrupt theload with the remaining cartridge. This 6 is an advantage since thelineman may be highin the air on the line pole while he is usingtheswitch stick mounted load break deviceand it is inconvenient for him toput in anew cartridge at this time. Of course, theswitch stick mountedload break device can be used while the lineman is on the ground or upon theline pole.

The fifth form of the invention differs from the preceding forms of theinvention in that the cartridge is rigidly mounted on the switch stick.-A- rigid mounting can be used in the third form of the invention.However, when the arm 31 of the third form of the invention is rigid theoperator must tilt the switch stick sideways during opening movement toinsure that the parts- 31, 23, 22 and 24 will ride-successively along,the contact latch 3. In the fifth formof the invention a rigid mountingfor the cartridge is used but without any necessity for sideways tiltingof the switch stick. Thus, asshown in- Fig. 12, this is accomplished byconnecting a resilient member suchas a leaf spring element 40 to theterminal 7 of contact latch 3. This requires no modification in thecutout since the terminal 7 is already provided. The cap 18 in thisinstance has a rigid arm 41 connected thereto which extends generallyperpendicular to the switch stick 20 and the hook 21. Arm 41 can beconnected to cap 18 by welding or other suitable means although it canbe made integral with the cap 18 which typically is true of hook 21 Atits outer end the arm 41 has cartridge holder 42 which is adapted tohave cartridge 22 mounted therein.

When the hook 21 is engaged with eyelet handle 16 the cartridge 22 willhave raised the spring. 40. This means that the spring 40 iscontinuously bearing down on the tip 24 as the fuseholder 2 is beingopened so that the tip 24 is the last point of electrical contactbetween the upper end of the fuseholder 2 and the contact latch 3.Therefore, the are which is drawn therebetween will terminate on the tip24. The are will burn through tip 24 whereby the compressed gas isreleased from cartridge 22 to cool and deionize theme. 7

In all forms of the invention the member or cartridge for interruptingthe load current are has been illustrated as being small withrespect tothe apparatus with which it is used and with respect to the switchstickon which it is mounted and carried, although this is not mandatory.However, a small one is preferred since then itwill be lightweight, lowcost, easy to handle, and convenient to use with conventional switchsticks and in the limited free space at conventional switches andcutouts. Since they are low cost they can be expendable withoutincurring high costs. Also, since they' are small several of them canconveniently be carried by a lineman in a cartridge magazine hooked onhis belt.

While there have been shown and described particular embodiments of theinvention, it will be obvious to those skilled in the art that changesand modifications may be made without departing from the invention, andtherefore, it is intended by the appended claims to cover all suchchanges and modifications as fall within the true spirit and scope ofthe invention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. A switch stick mounted load break device comprising a switch openingstick, said stick having a hook member mounted on one end thereof formanually opening a switch with said stick, and a small expendable andreplaceable electrical arc extinguishing member movably and resilientlymounted on the same end of said stick for extinguishing an electricalare which is drawn at a switch when it is opened with said stick, saidexpendable and replaceable member being mounted on said stick by an armwhich is connected to said one end and extends beyond said one end andcarries said electrical arc extinguishing member beyond said one end andsaid expendable and replaceable electrical arc extinguishing memberbeing small with respect to said stick and switch.

2. In a load break device as in claim 1, wherein said 'arm extends firstin a direction which is generally parallel to said stick and thengenerally transverse to said stick.

' 3. In a load break device as in claim 2, wherein said arm is pivotallyconnected to said one end and is biased by a spring.

4. In a load break device as in claim 2, wherein said arm is constructedfrom resilient material.

5. In a load break device as in claim 4, wherein the outermost generallytransverse direction of said arm is also generally transverse to saidhook member.

6. In a load break device as in claim 4, wherein the inner end of saidarm is coiled.

7. In a load break device as in claim 4, wherein the outermost generallytransverse direction of said arm is also generally parallel to said hookmember.

8. In a load break device as in claim 6, wherein a continuation of theinner coiled end of said arm provides a second arm which at itsoutermost end extends in a transverse direction opposite to the firstrecited arm and carries a second electrical arc interrupting member.

9. A device for manually separating an open-type switch member from acontact and extinguishing an electrical arc which is established betweensaid contact and switch member, said device comprising an electricallyinsulated switch stick having electrically conductive means on one endthereof which is adapted to be engaged with an electrically conductiveportion of said switch member for manually separating said switch memberfrom said contact, a small expendable and replaceable electricallyconductive cartridge which is mounted on the same end of said switchstick as said means and is in electrically conductive relationship withsaid means, said cartridge being adapted to produce a pressure blastinto said electrical arc in response to termination of said electricalarc thereon, and means for making said cartridge the last point ofelectrical contact between said switch member and said contact.

10. In a device as in claim 9, wherein said cartridge is mounted on saidswitch stick in an electrically conductive and movable cartridge holderwhich is electrically connected to said electrically conductive means,and said means for making said cartridge the last point of electricalcontact between said switch member and said contact comprises springmeans for moving said cartridge into contact with said contact as saidswitch member is being manually opened with said switch stick.

11. A device for manually separating an open-type switch member from acontact and extinguishing an electrical are which is established betweensaid contact and switch member, said device comprising an electricallyinsulated switch stick having an electrically conductive hook member onone end thereof which is adapted to be engaged with an electricallyconductive eyelet handle of said switch member, an electricallyconductive curved arm which is mounted on said one end in electricallyconductive relationship with said hook member, said arm extending awayfrom said one end first in a direction which is generally parallel tothe axis of said stick and then being curved in a direction which isgenerally transverse to said axis, an electrically conductive cartridgeholder mounted on the outer end of said arm, said holder having anelectrically conductive small expendable and replaceable cartridgetherein which is adapted to generate an electrical arc extinguishingpressure blast into said electrical arc in response to termination ofsaid are thereon, and spring means for making said cartridge the lastpoint of electrical contact between said switch member and said contactby biasing said arm and then said holder and then said cartridge intocontact with said contact as said switch member is being manually openedwith said stick.

12. A switch stick mounted load break device comprising a switch stickhaving an expendable and replaceable electrical arc extinguishing membermounted thereon which is adapted to extinguish an electrical are whichis established at an open-type switch member when said switch member ismanually opened with said switch stick, said electrical arcextinguishing member comprising a cartridge which is adapted to producea pressure blast into said electrical arc.

13. A switch stick mounted load break device comprising a switch stickhaving an expendable and replaceable electrical arc extinguishing membermounted thereon which is adapted to extinguish an electrical are whichis established at an open-type switch member when said switch member ismanually opened with said switch stick, said electrical arcextinguishing member comprising a cartridge which is adapted to producea pressure blast into said electrical arc in response to termination ofsaid electrical are on said cartridge.

References Cited in the file of this patent UNITED STATES PATENTS700,809 Partridge May 27, 1902 2,438,746 Garrison Mar. 30, 19482,671,145 Lindell Mar. 2, 1954 2,750,471 McBride June 12, 1956 2,752,458Baker et al. June 26, 1956 2,834,855 Carpenter et al. May 13, 19582,834,856 Charewicz et al. May 13, 1958

